What is quantum computing? – TechTarget
Quantum computing is an area of study focused on the development of computer based technologies centered around the principles ofquantum theory. Quantum theory explains the nature and behavior of energy and matter on thequantum(atomic and subatomic) level. Quantum computing uses a combination ofbitsto perform specific computational tasks. All at a much higher efficiency than their classical counterparts. Development ofquantum computersmark a leap forward in computing capability, with massive performance gains for specific use cases. For example quantum computing excels at like simulations.
The quantum computer gains much of its processing power through the ability for bits to be in multiple states at one time. They can perform tasks using a combination of 1s, 0s and both a 1 and 0 simultaneously. Current research centers in quantum computing include MIT, IBM, Oxford University, and the Los Alamos National Laboratory. In addition, developers have begun gaining access toquantum computers through cloud services.
Quantum computing began with finding its essential elements. In 1981, Paul Benioff at Argonne National Labs came up with the idea of a computer that operated with quantum mechanical principles. It is generally accepted that David Deutsch of Oxford University provided the critical idea behind quantum computing research. In 1984, he began to wonder about the possibility of designing a computer that was based exclusively on quantum rules, publishing a breakthrough paper a few months later.
Quantum Theory
Quantum theory's development began in 1900 with a presentation by Max Planck. The presentation was to the German Physical Society, in which Planck introduced the idea that energy and matter exists in individual units. Further developments by a number of scientists over the following thirty years led to the modern understanding of quantum theory.
Quantum Theory
Quantum theory's development began in 1900 with a presentation by Max Planck. The presentation was to the German Physical Society, in which Planck introduced the idea that energy and matter exists in individual units. Further developments by a number of scientists over the following thirty years led to the modern understanding of quantum theory.
The Essential Elements of Quantum Theory:
Further Developments of Quantum Theory
Niels Bohr proposed the Copenhagen interpretation of quantum theory. This theory asserts that a particle is whatever it is measured to be, but that it cannot be assumed to have specific properties, or even to exist, until it is measured. This relates to a principle called superposition. Superposition claims when we do not know what the state of a given object is, it is actually in all possible states simultaneously -- as long as we don't look to check.
To illustrate this theory, we can use the famous analogy of Schrodinger's Cat. First, we have a living cat and place it in a lead box. At this stage, there is no question that the cat is alive. Then throw in a vial of cyanide and seal the box. We do not know if the cat is alive or if it has broken the cyanide capsule and died. Since we do not know, the cat is both alive and dead, according to quantum law -- in a superposition of states. It is only when we break open the box and see what condition the cat is in that the superposition is lost, and the cat must be either alive or dead.
The principle that, in some way, one particle can exist in numerous states opens up profound implications for computing.
A Comparison of Classical and Quantum Computing
Classical computing relies on principles expressed by Boolean algebra; usually Operating with a 3 or 7-modelogic gateprinciple. Data must be processed in an exclusive binary state at any point in time; either 0 (off / false) or 1 (on / true). These values are binary digits, or bits. The millions of transistors and capacitors at the heart of computers can only be in one state at any point. In addition, there is still a limit as to how quickly these devices can be made to switch states. As we progress to smaller and faster circuits, we begin to reach the physical limits of materials and the threshold for classical laws of physics to apply.
The quantum computer operates with a two-mode logic gate:XORand a mode called QO1 (the ability to change 0 into a superposition of 0 and 1). In a quantum computer, a number of elemental particles such as electrons or photons can be used. Each particle is given a charge, or polarization, acting as a representation of 0 and/or 1. Each particle is called a quantum bit, or qubit. The nature and behavior of these particles form the basis of quantum computing and quantum supremacy. The two most relevant aspects of quantum physics are the principles of superposition andentanglement.
Superposition
Think of a qubit as an electron in a magnetic field. The electron's spin may be either in alignment with the field, which is known as aspin-upstate, or opposite to the field, which is known as aspin-downstate. Changing the electron's spin from one state to another is achieved by using a pulse of energy, such as from alaser. If only half a unit of laser energy is used, and the particle is isolated the particle from all external influences, the particle then enters a superposition of states. Behaving as if it were in both states simultaneously.
Each qubit utilized could take a superposition of both 0 and 1. Meaning, the number of computations a quantum computer could take is 2^n, where n is the number of qubits used. A quantum computer comprised of 500 qubits would have a potential to do 2^500 calculations in a single step. For reference, 2^500 is infinitely more atoms than there are in the known universe. These particles all interact with each other via quantum entanglement.
In comparison to classical, quantum computing counts as trueparallel processing. Classical computers today still only truly do one thing at a time. In classical computing, there are just two or more processors to constitute parallel processing.EntanglementParticles (like qubits) that have interacted at some point retain a type can be entangled with each other in pairs, in a process known ascorrelation. Knowing the spin state of one entangled particle - up or down -- gives away the spin of the other in the opposite direction. In addition, due to the superposition, the measured particle has no single spin direction before being measured. The spin state of the particle being measured is determined at the time of measurement and communicated to the correlated particle, which simultaneously assumes the opposite spin direction. The reason behind why is not yet explained.
Quantum entanglement allows qubits that are separated by large distances to interact with each other instantaneously (not limited to the speed of light). No matter how great the distance between the correlated particles, they will remain entangled as long as they are isolated.
Taken together, quantum superposition and entanglement create an enormously enhanced computing power. Where a 2-bit register in an ordinary computer can store only one of four binary configurations (00, 01, 10, or 11) at any given time, a 2-qubit register in a quantum computer can store all four numbers simultaneously. This is because each qubit represents two values. If more qubits are added, the increased capacity is expanded exponentially.
Quantum Programming
Quantum computing offers an ability to write programs in a completely new way. For example, a quantum computer could incorporate a programming sequence that would be along the lines of "take all the superpositions of all the prior computations." This would permit extremely fast ways of solving certain mathematical problems, such as factorization of large numbers.
The first quantum computing program appeared in 1994 by Peter Shor, who developed a quantum algorithm that could efficiently factorize large numbers.
The Problems - And Some Solutions
The benefits of quantum computing are promising, but there are huge obstacles to overcome still. Some problems with quantum computing are:
There are many problems to overcome, such as how to handle security and quantum cryptography. Long time quantum information storage has been a problem in the past too. However, breakthroughs in the last 15 years and in the recent past have made some form of quantum computing practical. There is still much debate as to whether this is less than a decade away or a hundred years into the future. However, the potential that this technology offers is attracting tremendous interest from both the government and the private sector. Military applications include the ability to break encryptions keys via brute force searches, while civilian applications range from DNA modeling to complex material science analysis.
See the rest here:
What is quantum computing? - TechTarget
- Building the world's first open-source quantum computer - Phys.org - January 22nd, 2026 [January 22nd, 2026]
- Rigetti: Not The Quantum Computing Stock To Own - There Are Better Alternatives - Seeking Alpha - January 22nd, 2026 [January 22nd, 2026]
- IQM and Bechtle to install five-qubit quantum computer at Heilbronn University, Germany - BeBeez International - January 22nd, 2026 [January 22nd, 2026]
- Exclusive from 36Kr: Team with Tsinghua and Harvard Backgrounds Developing Quantum Computers, Revenues Double, Secures Hundreds of Millions in... - January 22nd, 2026 [January 22nd, 2026]
- Quantum error correction with logical qubits - EurekAlert! - January 22nd, 2026 [January 22nd, 2026]
- These 3 Giant Tech Stocks Are Poised for Explosive Quantum Growth - The Motley Fool - January 22nd, 2026 [January 22nd, 2026]
- The quantum-cryptography cliff: From roadmaps to reality - SC Media - January 22nd, 2026 [January 22nd, 2026]
- MIT Researchers Demonstrate Faster Cooling Method for Chip-Based Trapped-Ion Quantum Systems - The Quantum Insider - January 22nd, 2026 [January 22nd, 2026]
- It started with a cat: How 100 years of quantum weirdness powers todays tech - Texas A&M Stories - January 22nd, 2026 [January 22nd, 2026]
- The Smartest Quantum Computing Stock to Buy for 2026 - The Motley Fool - January 22nd, 2026 [January 22nd, 2026]
- Network-based Quantum Computing Achieves Distributed Fault-Tolerance with Many Small Nodes - Quantum Zeitgeist - January 22nd, 2026 [January 22nd, 2026]
- RGTI and QUBT: This Analyst Sees the Next Jump in Quantum Stocks - Yahoo Finance - January 22nd, 2026 [January 22nd, 2026]
- Building the worlds first open-source quantum computer - University of Waterloo - January 20th, 2026 [January 20th, 2026]
- The 3 Best Quantum Computing Stocks to Buy for 2026 - Yahoo Finance - January 14th, 2026 [January 14th, 2026]
- Safeguard Your WAN from Quantum Computing Threats - Cisco Blogs - January 14th, 2026 [January 14th, 2026]
- PsiQuantum Collaborating with Airbus to Advance Quantum Computing for Aerospace - HPCwire - January 14th, 2026 [January 14th, 2026]
- Putting Quantum Computing to the Test - University of Pittsburgh - January 14th, 2026 [January 14th, 2026]
- Xanadu and Thorlabs Partner to Advance Optical Controls for Photonic Quantum Computing - HPCwire - January 14th, 2026 [January 14th, 2026]
- Why Quantum Computers Are Inherently Reversible (And Why That Matters) - Quantum Zeitgeist - January 14th, 2026 [January 14th, 2026]
- 1 Quantum Computing Stock to Buy that Could Soar in 2026 - The Motley Fool - January 14th, 2026 [January 14th, 2026]
- BTQ Technologies Added to VanEck Quantum Computing UCITS ETF, Expanding European Access to BTQ Through a Regulated UCITS Wrapper - PR Newswire - January 14th, 2026 [January 14th, 2026]
- Singapore and Japan team up on quantum computing - Computer Weekly - January 14th, 2026 [January 14th, 2026]
- Will Quantum Computing Stocks Become the AI Stocks of 2026? - The Motley Fool - January 14th, 2026 [January 14th, 2026]
- Silicon vibrations add a new twist to dark matter research and quantum computing - The Brighter Side of News - January 14th, 2026 [January 14th, 2026]
- D-Wave Just Got a Formidable Quantum Computing Ally. Should You Buy QBTS Stock Here? - Yahoo Finance - January 14th, 2026 [January 14th, 2026]
- 1 Quantum Computing Stock to Buy that Could Soar in 2026 - AOL.com - January 14th, 2026 [January 14th, 2026]
- Yaqumo Inc. and Entropica Labs Sign MOU, Witnessed by Singapore and Japan Governments, to Accelerate Fault-Tolerant Quantum Computing - The Quantum... - January 14th, 2026 [January 14th, 2026]
- Quantum Advantage Has Likely Been Achieved The Debate Is Over What Counts - The Quantum Insider - January 14th, 2026 [January 14th, 2026]
- Will quantum computing stocks become the AI stocks of 2026? - MSN - January 14th, 2026 [January 14th, 2026]
- Quantum Computing Stocks To Add to Your Watchlist - January 12th - MarketBeat - January 14th, 2026 [January 14th, 2026]
- Quantum computing revives debate over Bitcoins long-term security - Mugglehead Magazine - January 14th, 2026 [January 14th, 2026]
- Quantum AI: Telco's Next Big Thing or Expensive Distraction? - Telecoms - January 14th, 2026 [January 14th, 2026]
- What does a quantum computer sound like? This artist and scientist are about to find out - Financial Times - January 11th, 2026 [January 11th, 2026]
- Bipartisan Sens. Give Quantum Reauthorization Act Another Chance - MeriTalk - January 11th, 2026 [January 11th, 2026]
- 3 Quantum Computing Stocks That Could Make a Millionaire - The Motley Fool - January 9th, 2026 [January 9th, 2026]
- Infleqtion and Churchill X Move Forward on SPAC Combination - The Quantum Insider - January 9th, 2026 [January 9th, 2026]
- Quantum computing has advantages over traditional, but still in early innings: BMO (IONQ:NYSE) - Seeking Alpha - January 9th, 2026 [January 9th, 2026]
- D-Wave Buys Quantum Circuits in Shift to Higher Gear - EE Times - January 9th, 2026 [January 9th, 2026]
- Beyond the Hype: 5 Reasons Quantum Computing Stocks IonQ, Rigetti Computing, and D-Wave Quantum Can Crash in 2026 - Nasdaq - January 9th, 2026 [January 9th, 2026]
- Quantum neural network may be able to cheat the uncertainty principle - New Scientist - January 9th, 2026 [January 9th, 2026]
- Q&A: What does cybersecurity look like in the quantum age? - Penn State University - January 9th, 2026 [January 9th, 2026]
- D-Wave Demo At CES 2026 And The Energy Efficiency Of Quantum Computing - Quantum Zeitgeist - January 9th, 2026 [January 9th, 2026]
- Quantum Computers Extract Scattering Phase Shift In One-Dimensional Systems Using Integrated Correlation Functions - Quantum Zeitgeist - January 9th, 2026 [January 9th, 2026]
- How John Clarke's Nobel Prize-Winning Research Paved the Way for Quantum Computing - Berkeley Lab News Center (.gov) - January 9th, 2026 [January 9th, 2026]
- Circle Examines How Crypto and Web3 Ecosystems are Preparing Blockchains for the Quantum Era - Crowdfund Insider - January 9th, 2026 [January 9th, 2026]
- The Best Quantum Computing Stock to Buy Hand Over Fist in 2026 - The Motley Fool - January 9th, 2026 [January 9th, 2026]
- Quantum computing is closer than you think - Federal News Network - January 9th, 2026 [January 9th, 2026]
- Quantum computing company D-Wave acquires new tech in major merger - Washington Times - January 9th, 2026 [January 9th, 2026]
- Josephson junctions quantum computing building blocks are possible with only one superconductor, experiment confirms - Technology Org - January 9th, 2026 [January 9th, 2026]
- After a Year of Quantum Awareness, 2026 Becomes the Year of Quantum Security - The Quantum Insider - January 9th, 2026 [January 9th, 2026]
- The best quantum computing stock to buy hand over fist in 2026 - MSN - January 9th, 2026 [January 9th, 2026]
- Google Willow: The secrets of the world's most powerful quantum computer - BBC - January 8th, 2026 [January 8th, 2026]
- D-Wave: Quantums First Real Revenue Winner (NYSE:QBTS) - Seeking Alpha - January 8th, 2026 [January 8th, 2026]
- D-Wave to Buy Quantum Circuits for $550 Million. Useful Computers Are Coming to Market. - Barron's - January 8th, 2026 [January 8th, 2026]
- DARPA seeks universal translator between different kinds of quantum computer - Breaking Defense - January 8th, 2026 [January 8th, 2026]
- Royal Bank, Telus back $130-million financing by quantum developer Photonic - The Globe and Mail - January 8th, 2026 [January 8th, 2026]
- Qubits Can be Cloned: Scientists Discover First Method to Safely Back up Quantum Information - The Quantum Insider - January 8th, 2026 [January 8th, 2026]
- The Smartest Quantum Computing Stock to Buy for 2026 - Yahoo Finance - January 8th, 2026 [January 8th, 2026]
- 3 Top Quantum Computing Stocks to Buy in 2026 - The Motley Fool - January 8th, 2026 [January 8th, 2026]
- Fredkin And Toffoli: The Architects Of Reversible Computation - Quantum Zeitgeist - January 8th, 2026 [January 8th, 2026]
- Quantum Resistance LLC on the Future of Digital Security in a World of Emerging Quantum Computing - International Business Times - January 8th, 2026 [January 8th, 2026]
- Moscow State University and Rosatom Test 72-Qubit Neutral-Atom Quantum Prototype - Quantum Computing Report - January 8th, 2026 [January 8th, 2026]
- Prediction: These 4 quantum computing stocks will skyrocket in 2026 - MSN - January 8th, 2026 [January 8th, 2026]
- D-Wave Rises On Quantum First - Yahoo Finance - January 8th, 2026 [January 8th, 2026]
- Are Quantum Computing ETFs the Safest Bet for 10-Year Growth? - Nasdaq - January 8th, 2026 [January 8th, 2026]
- Tech and compliance 2026: What to watch for in AI, cybersecurity and quantum computing - Compliance Week - January 8th, 2026 [January 8th, 2026]
- Using microwave pulses to plug leaks in quantum computers makes them more reliable - Phys.org - December 29th, 2025 [December 29th, 2025]
- 5 Major Quantum Computing Breakthroughs that Shaped 2025 - TipRanks - December 29th, 2025 [December 29th, 2025]
- D-Wave stock slides into year-end as quantum peers retreat in thin trade - ts2.tech - December 29th, 2025 [December 29th, 2025]
- Quantum Computing Trends in 2025: Data Reveals Hardware Bets, Cloud Growth And Security Focus - The Quantum Insider - December 29th, 2025 [December 29th, 2025]
- The Neglecton: How Mathematical 'Garbage' Saved The Quantum Computer - Quantum Zeitgeist - December 29th, 2025 [December 29th, 2025]
- Quantum science and technology: highlights of 2025 - Physics World - December 29th, 2025 [December 29th, 2025]
- Are These 2 Quantum Computing Stocks the Key to Decades of Wealth? - The Motley Fool - December 29th, 2025 [December 29th, 2025]
- The Man Who Knew Too Much: Why Ettore Majoranas 1938 disappearance still haunts quantum computing. - Quantum Zeitgeist - December 29th, 2025 [December 29th, 2025]
- Breaking The Code: How Peter Shor Proved Quantum Power Was Real - Quantum Zeitgeist - December 29th, 2025 [December 29th, 2025]
- Opinion: Quantum computing is the stock markets next big tech play and these stocks are still cheap - MarketWatch - December 29th, 2025 [December 29th, 2025]
- Quantum computing made measurable progress toward real-world use in 2025 - TechSpot - December 29th, 2025 [December 29th, 2025]
- IonQ drops with quantum peers into year-end, as investors weigh next catalysts - ts2.tech - December 29th, 2025 [December 29th, 2025]
- Forget Rigetti Computing: This Quantum Stock Offers a Far Better Risk-Reward Right Now - Finviz - December 29th, 2025 [December 29th, 2025]
- Quantum Computing Stocks: IonQ, Rigetti, D-Wave and QUBT Slide Into Year-EndWhat to Watch Before Mondays Open - ts2.tech - December 29th, 2025 [December 29th, 2025]